Steampunk Copper vs Copper (Metallic)

How close are they?

ΔE 27.0, loose: different enough that you should pick on purpose. Copper (Metallic) is noticeably lighter, much more muted than Steampunk Copper.

Can I use Copper (Metallic) instead of Steampunk Copper?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 27). Copper (Metallic) is noticeably lighter, much more muted than Steampunk Copper.

Can I use Steampunk Copper instead of Copper (Metallic)?

The same difference applies the other way round: Steampunk Copper is noticeably darker, much more saturated.

ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.